Impact of electrostatics and doping concentration on the performance of silicon tunnel field-effect transistors

We present experimental studies on the performance of ultra-thin body SOI tunnel FETs depending on channel length, gate oxide thickness and source/drain doping concentrations. Electrical measurements show no dependance on channel length, however, a strong dependance on gate oxide thickness and doping concentration is found. Our experimental results match calculations based on a simple Landauer model employing the Wenzel–Kramer–Brillouin approximation for the tunneling process. Bandgap narrowing and the electrostatics of the tunneling junction are found to be the main factors impacting the on-state performance of the tunnel FET.